The present invention relates generally to the printing of continuous forms by a computer-controlled printing device and, more particularly, to a leader for feeding a single form or the first of a series of forms into the printing device.
In recent years, computers have become an increasingly popular and useful tool for large and small business as well as for individuals. One common use for computers, utilizing the ability of a computer to drive a printing device, is the preparation of preprinted forms. Such forms are used for many documents, such as checks, invoices, purchase orders, other business records and the like.
Forms for such use are typically supplied in a continuous web with each individual form divided by perforations for separation of the forms after printing. The web is fed through a printing device, where large numbers of such forms can be printed in rapid succession, using information stored and supplied by the computer.
A typical arrangement for a printing device for printing forms is shown in FIG. 1. A web 10 comprises a series of successive forms, with the web 10 being provided with a series of equally spaced line holes 12 along each edge of the web. The positioning of such holes is in accordance with generally accepted industry standards, with the most common spacing between successive holes 12 being 1/2" (1.27 cm) center-to-center.
The printing device includes a print head 14 connected to an appropriate carriage structure 16 for lateral movement of print head 14 as indicated by arrow 18. The web 10 enters the device and passes around a roller 20 which directs the web beneath print head 14. A second roller 22 is provided with a series of pins 24 at each of its ends, the pins 24 being arranged so as to engage the line holes 12 of the web 10 as it passes around roller 22. (Such a pin and wheel arrangement is often referred to as a "tractor wheel".) Suitable hold-down rollers 26 or the like are also provided to keep the web 10 in engagement with roller 22 and pins 24.
Roller 22 is connected to a motor 28 for driving the roller in a direction indicated by arrow 30. This moves the web 10 through the printing device as indicated by arrow 32, so that the web is advanced with respect to print head 14 for printing of the web. In addition, roller 22 is connected to a hand-operated knob 34 which can be used to manually advance roller 22 for making adjustments in the positioning of web 10.
Of course, common concerns in the purchase, printing and subsequent use of forms include maximizing efficiency and economy. To a large extent, efficiency is enhanced by using a high-speed printing device. Increasing economy is approached by keeping waste of individual forms to an absolute minimum. This latter concern is important, since complex, multi-part forms can frequently cost as much as 20 cents or more per form.
One problem which can be seen from a review of FIG. 1 is that the web of forms 10 is driven by a roller 22 which is located further along the paper path of the printing device than print head 14. Consequently, in order to print the upper portion of a single form, it is necessary for the form to be preceded by some portion of the web. This is no problem where the particular form in question represents one of a series of forms to be printed, but where only a single form is to be prepared, or the form represents the first of a series of forms to be printed, it can be seen that there is no way for the upper portion of this form to be printed within the device.
The typical solution to this problem is to insert the web into the printing device and advance the web beyond the first form in the series. Of course, this wastes the first form, but there is little choice since printing upon this form is not possible. Not only does this represent an economic disadvantage, but also an efficiency disadvantage in that it can complicate bookkeeping procedures. Many forms, such as checks, invoices and the like, are prenumbered in sequence for bookkeeping purposes. Frequent waste of the first form of a series to be printed results in many numbers for which the form was ultimately discarded. Accounting for these unused numbers can be a great inconvenience.
What is needed, therefore, is a means by which waste of the first form of a series of preprinted forms can be avoided. Such a means would enable the upper portion of the initial form to be printed by the printing device, thereby rendering such a form usable. Of course, such a means must be relatively inexpensive, since it must cost less than the otherwise wasted forms to be economically practical.